Boosting photocatalytic CO2 reduction in a ZnS/ZnIn2S4 heterostructure through strain-induced direct Z-scheme and a mechanistic study of molecular CO2 interaction thereon

Sabbah A.Qorbani M.Fu F.-Y.Lin T.-Y.Wu H.-L.CHIH-I WUChen K.-H.LI-CHYONG CHEN2022-08-092022-08-09202222112855https://www.scopus.com/inward/record.uri?eid=2-s2.0-85121146399&doi=10.1016%2fj.nanoen.2021.106809&partnerID=40&md5=adc3f3dcf4bc90b7b47d985ef2a4742chttps://scholars.lib.ntu.edu.tw/handle/123456789/616353Employing direct Z-scheme semiconductor heterostructures in photocatalysis offers efficient charge carrier separation and isolation of both redox reactions, thus beneficial to reduce CO2 into solar fuels. Here, a ZnS/ZnIn2S4 heterostructure, comprising cubic ZnS nanocrystals on hexagonal ZnIn2S4 (ZIS) nanosheets, is successfully fabricated in a single-pot hydrothermal approach. The composite ZnS/ZnIn2S4 exhibits microstrain at its interface with an electric field favorable for Z-scheme. At an optimum ratio of Zn:In (~ 1:0.5), an excellent photochemical quantum efficiency of around 0.8% is reached, nearly 200-fold boost compared with pristine ZnS. Electronic levels and band alignments are deduced from ultraviolet photoemission spectroscopy and UV-Vis. Evidence of the direct Z-scheme and carrier dynamics is verified by photo-reduction experiment, along with photoluminescence (PL) and time-resolved PL. Finally, diffuse-reflectance infrared Fourier transformed spectroscopy explores the CO2 and related intermediate species adsorbed on the catalyst during the photocatalytic reaction. This microstrain-induced direct Z-scheme approach opens a new pathway for developing next-generation photocatalysts for CO2 reduction. © 2021 Elsevier LtdCO2 reduction;Interfacial charge transfer;Photocatalysis;Z-Scheme;ZnIn2S4;ZnS[SDGs]SDG7[SDGs]SDG13Carbon dioxide;Charge transfer;Electric fields;Heterojunctions;II-VI semiconductors;Indium compounds;Photocatalysis;Photoelectron spectroscopy;Reaction intermediates;Zinc sulfide;Carrier separation;CO 2 reduction;Interfacial charge transfer;Mechanistic studies;Micro-strain;Photo-catalytic;Semiconductor heterostructure;Solar fuels;Strain induced;Z-scheme;Redox reactionsBoosting photocatalytic CO2 reduction in a ZnS/ZnIn2S4 heterostructure through strain-induced direct Z-scheme and a mechanistic study of molecular CO2 interaction thereonjournal article10.1016/j.nanoen.2021.1068092-s2.0-85121146399